WASHINGTON, D.C.—The incidence of renal stones has doubled among adolescents over a 25-year period, but has remained stable in younger individuals, according to a study conducted in Olmsted County, Minnesota.

Amy Krambeck, MD, and colleagues at Mayo Clinic in Rochester, Minn., identified 84 children total aged 0-17 years who were valid incident stone formers from 1984 to 2008. They estimated the incidence per 100,000 person-years of risk standardized to the 2000 U.S. Census age-sex distribution. The overall stone incidence rates were 13 per 100,000 person-years for females and 9 per 100,000 person-years for males. The researchers observed no statistically significant difference in incidence among genders, however. Among subjects aged 12-17 years, the incidence of kidney and ureteral stones increased from about 13 per 100,000 person-years in 1984-1990 to 36 per 100,000 person-years in 2003-2008, according to findings presented at the American Urological Association 2011 annual meeting. This rise led to an overall increase in incidence of 4% per year over the 25-year study period. 

“This epidemiologic study confirms previous observations from tertiary care centers who have reported a rise in symptomatic pediatric stone disease,” said Dr. Krambeck, Assistant Professor of Medicine at the Mayo School of Graduate Medical Education. “Based on the results of this study, we cannot speculate the cause for the rise in stone disease in the adolescent population, but body weight does not appear to be an influencing factor.”